PROCESS DEVELOPMENT AND OPTIMIZATION USING A NEWLY DESIGNED CONFORMAL COATING TEST VEHICLE

Abstract: There are test vehicles to address SMT assembly process development and optimization, but none to address Conformal Coating operations. To fill this gap, Celestica has designed the “CC-Tango” test vehicle. The continued migration in the electronics industry for higher density components and smaller footprint layouts makes the conformal coating process more challenging in terms of achieving acceptable first pass process yields. The “CCTango” test vehicle has the capability to assess keep-out tolerances, coverage and overall pattern definition. These are some of the main features that require further investigation for design optimization. This information is critical for Aerospace, Military, Industrial customers and any other products that may be exposed to harsh environmental conditions with either lead free or mixed conditions requiring Conformal Coating.

This paper will describe how we have used this test vehicle to evaluate Conformal Coating materials, compare application equipment along with providing site enablement and optimization methods for Conformal Coating processes.

Sixteen process variables were investigated. The three most critical variables were identified and their impacts will be discussed. IPC-CC-830[3] and IPC-TM-650[6-13] standards were used to execute the test plan.